I'm having a VERY annoying issue...
If I shut down my PC. Then when I turn it on again the displays do not activate. The PC will boot up but no displays will work. My DTH2G's light is red. The only way I can get it to work is to plug in one of my monitors, start the bootup and then hot swap it to the DTH2G. Then it works fine for restarts and everything until I shut down again. It is driving me nuts!
I have two nVidia 8800 GTX SLI gfx card setup.
Sounds like you're having the same problem some guys on [H] were:
http://www.hardforum.com/showthread.php?t=1225164
Try unplugging the power (usb) before rebooting.